Query regarding Central and peripheral || Advertisement

RE: Query regarding Central and peripheral || Advertisement

Rakesh R — Sun, 10 May 2020 15:38:55 GMT

Okay got it, thanks for the answer.

RE: Query regarding Central and peripheral || Advertisement

Dmitry — Sun, 10 May 2020 15:36:20 GMT

You cannot have two sets of advertisements with different parameters working in parallel. The only way is to switch between "low power" and "high power" packets dynamically.

RE: Query regarding Central and peripheral || Advertisement

Rakesh R — Sun, 10 May 2020 15:24:03 GMT

Hi Dmitry,

for the prompt response.

I got your point here for transmission power of advertising packet, but it still seems some confusion.

let me ask it again.

i need to find the device in particular range, there is two categories of range let's say one is up to 8 feet and other is 8-20 feet,.

so now i will have device which will advertise two advertisement packets, one with low power and one with high power.

so power will be fixed initially, no need to change power dynamically.

so both advertisement packets will have there own configuration.

RE: Query regarding Central and peripheral || Advertisement

Dmitry — Sun, 10 May 2020 15:12:29 GMT

[quote userid="90186" url="~/f/nordic-q-a/61218/query-regarding-central-and-peripheral-advertisement/249054"]Can I have two different advertisement packets with two different power??? Power will be fixed for each advertisement packet.[/quote]

You can dynamically change the content of advertising packet, switching between them, see here. Concerning different power - as I answered above, there is an API to change advertising power, though I didn't try to change it on the fly, maybe you will have a luck.

RE: Query regarding Central and peripheral || Advertisement

Rakesh R — Sun, 10 May 2020 08:52:05 GMT

Hi Dmitry,

Thanks for the reply.

1) Can I have two different advertisement packets with two different power??? Power will be fixed for each advertisement packet.

RE: Query regarding Central and peripheral || Advertisement

Dmitry — Sat, 09 May 2020 21:50:25 GMT

Hi,

1) yes, you can configure a broadcaster and an observer along with a connection.

2) there is always a chance of packet loss, even when scanning a single device, there are too many devices at 2.4Ghz band causing interference. Also, more devices are on air, more chances for collisions. In your case, assuming 100 devices are advertising with 2-second interval and payload is 31 bytes (whole packet takes about 400us on-air time), one can expect about 2% chance of collision, that is quite good.

3) you can change TX power with sd_ble_gap_tx_power_set() API call (I can't say for sure whether you can change TX power on the fly, maybe you will need to restart advertising to change power).

4) is AoA/AoD positioning an option for you?